Jardine et al, (J. Chem. Soc (C), 270 (1967)) have described the preparation of saturated aldehydes by hydrogenation of unsaturated aldehydes, using tris(triphenylphosphine)chlororhodium. However, to promote the hydrogenation while minimizing the risk of decarbonylation, dilute solutions of the unsaturated aldehyde must be employed, and this makes it difficult to isolate the reaction product or to operate at a high hydrogen pressure. This leads to the formation of a large quantity of the corresponding saturated alcohol.
It is also known, according to C. Larpent et al., (Tetrahedron Letters, 28 (22) 2507 (1987)), to hydrogenate olefins in an aqueous two-phase medium, using rhodium complexes with water-soluble ligands such as tri(metasulphophenyl)phosphine (TPPTS) as a catalyst, it being possible for the olefins to be functionally substituted by groups which are difficult to reduce such as ketone or acid functional groups.